Speed Tweaks от Benthum

Speed Tweaks is an addon that help you speed-up your browser by using seven different tweaks. Simply open toolbar popup UI and mark a desired item (or click on the desired tweak for action buttons). Please note that, none of these tweaks are selected by default.

Currently there are 7 tweaks available for this addon:
1. Blocking most common ads.
2. DNS Prefetching.
3. Blocking images from loading.
4. Speed up rendering on page scroll.
5. Loading mobile version of sites.
6. Discarding all inactive tabs from memory.
7. Clearing the browser's cache.

Note #1: depending on your browser version and platform, this addon might behave differently.

Note #2: in order to report bugs, please fill the bug report form in the addon's homepage.